Project Summary The process combining supercritical CO2 and co-sterilants produces strong synergistic microbicidal effects in relatively mild conditions. The mechanism of microbe inactivation is not well characterized, but the disruption of lipid membranes and mild oxidative damage appear to be involved. The process, which is also highly efficient against viruses, is considered to be very mild compared to other sterilization methods. Experimental evidence shows that damage to protein is limited, and that immunogenic epitopes can survive the process. In this project NovaSterilis will seek to optimize the supercritical CO2 sterilization process for broad and effective virucidal treatments while attempting to maintain the integrity of model proteins. The first goal is to fully validate the supercritical process against viruses as a method that could replace ?-radiations which fail at effective virus inactivation and damage sensitive products. The second goal will be to characterize and optimize the supercritical sterilization process for the sterilization of proteins. Proteins have become increasingly popular as vaccines, therapeutics, and in combination devices. Yet, their sterilization remains extremely challenging. In collaboration with the group of Bryce Chackerian at the University of New Mexico, and Dr. Stephen Eyles and Professor Igor Kaltashov at UMass-Amherst, the effect of supercritical sterilization on growth factors and recombinant vaccines will be studied with in vitro and in vivo functional assay, and will for the first time use state-of-the-art mass spectrometry to determine with great precision the effect of scCO2 itself or combined with a sterilant on the conformation and oxidation status of model proteins.